Drawer locking device



May 20, 1958 P. ERISMANN 2,835,547

DRAWER LOCKING DEVIICEL Filed April 22, 1955 E /II INVENTOR.

PAUL ERISMANN BY WWW, fiwwflml ATTORNEYS Patented May 20, 1958 2,835,547DRAWER LocKmG DEVICE Paul Erisniann, Lucerne, Switzerland ApplicationApril 22, 1955, Serial No. 503,194 Claims priority, applicationSwitzerland April 23, 1954 1 Claim. (Cl. 312-219 The present inventionrelates to a drawer locking device in chests of drawers and the like inwhich a plurality of drawers are slidably arranged in one or more rowswhich usually are vertical but may be horizontal, each of the saiddrawers being provided with a swingable locking hook adapted to engage alocking member which is common to a plurality of drawers, in order tolock the drawer in its closed position by such engagement.

In known devices of this kind the said common locking member can berotated from outside the chest of drawers or the like about an axiswhich is parallel to the axes about which the locking hooks of thedrawers are swingable, in order to disengage from a central point thesaid locking hooks of all the drawers from their common locking member.It is also known to provide each of the locking hooks with a springtending to swing that hook into an active position in which it engagesthe common locking member provided that the latter is in its lockingposition, so that the locking hook automatically snaps into engagementwith the common locking member, thus locking the drawer, as soon as thelatter is shifted into its closed position. Each of the hooks has a noseadapted to engage from behind a locking surface of the common lockingmember.

Known centrally operatable locking devices of this kind have theinconvenience that a considerable force may be required to rotate thecommon locking member into its unlocking position, if this lockingmember is in engagement with a large number of locking hooks and ifmoreover the drawers are occupied by heavy objects such as tools. Forthis reason, the number of drawers which could be centrally locked orunlocked from a single point has been very limited. The saidconsiderable force required was due to the nature of relative motionbetween the common locking member and the locking hooks in the unlockingoperation. Up to now, the common locking member usually was shaped andsupported in such a manner that when it was rotated into its unlockingposition, its locking surface had to slide along the cooperatingsurfaces of the several locking hooks, in which sliding motioncomparatively high frictional forces depending on the number of lockinghooks and the weight of the contents of the drawers, i. e. on thepressure exerted on the said cooperating surfaces of the common lockingmember and of the locking hooks had to be overcome.

It is an object of the present invention to avoid the describeddrawbacks of the known centrally operatable locking devices of thiskind. 7 According to the invention, the common locking member isrotatable about such an axis that on its rotation into its unlockingposition its locking surface adapted to co-operate with the noses of thelocking hooks passes from a position at right angles from the slidingdirection of the drawers to a position at such an angle to saiddirection that the said locking surface is lifted off the co-operatingsurfaces of the hook noses and causes the locking hook of each drawer toslide off from the said locking surface of the common locking memberwhen this drawer is drawn to open it.

Preferably, the common locking member has an edge bounding its saidlocking surface and so disposed that on rotation of the common lockingmember into its unlocking position, it moves towards the locking hooksand swings them into a position in which they are at least partiallydisengaged from the locking surface of the common locking member.

Moreover, the axis of rotation of the common locking member may bearranged in such a position with respect to that occupied in closedcondition of the drawers by the axes about which their locking hooks areswingable and by the noses of these hooks, that when a drawing force isexerted on any drawer, this force does not result in any appreciablecouple on the common locking member which would tend to rotate thelatter into its unlocking position.

The common locking member may be a prismatic shaft, preferably of squarecross-section, which is rotatable by an angle approximately equal tohalf the angle formed by two adjacent faces of the shaft.

Further objects and advantages of the invention will become apparentfrom the description now to follow of a preferred embodiment thereof,given by way of example only; in this description, reference will be hadto the accompanying drawing in which:

Fig. 1 shows, in perspective view from the rear, a chest of drawers inwhich part of the chest walls have been broken away to show the drawerlocking device according to the invention;

Fig. 2 is a longitudinal vertical section through the common lockingmember and its bearings;

Fig. 3 is a cross-section taken on line III-III of Fig. 2;

Fig. 4 shows the said common locking member in crosssection and the rearpart of a drawer with its locking hook in plan view, the said commonlocking member being in its locking position; and

Fig. 5 is a view corresponding to that ofFig. 4 but showing the parts inunlocking position.

As shown in Fig; l, a plurality of drawers 11 are arranged one above theother in a chest 10 in which they are slidably supported each on a pairof angle rails 12. The rails 12 may be secured, for instance, to theside walls of the chest 10. Obviously, the drawers could as well besupported in known manner on a set of rollers to facilitate theirdrawing and closing. Each of the drawers can individually be drawn outof the. chest 10 at the front thereof'which is on the remote side asseen in Fig. 1.

At its rear end, each drawer 11 carries an extension 13 rigidly fixed toit, on which extension a locking hook 14 is swingably supported by meansof a vertical pin 15. This locking hook has a nose l6 and an extension17 which forms an abutment co-operating with the rear wall of the drawer11 for limiting the angle by which the hook 14 may be rotated in thedirection of the arrow P in Fig. 4. Further, each locking hook is actedupon by a torsion spring 18 one end leg of which engages the rear wallof the drawer lit and the opposite end leg of which engages the lockingbook 14- itself. This spring 18 tends to rotate the locking hook in thedirection of the arrow P of Fig. 4 so far as permitted by the extension17. The outer or rear face Not the hook nose 16 is shaped as an obliquegliding surface.

Near the rear wall of the chest it), a prismatic shaft 20 of squarecross-section is supported so that its axis is vertical, that is,parallel to the axes of the pins 15 on which the locking hooks M arepivoted. This shaft 20 forms a common locking member which cooperateswith the locking hooks in of all the drawers 11. End pieces 21 and 22are inserted into the ends of the hollow square shaft 29 and welded orsoldered to it. The por- I tions of the end pieces 21 and 2?. whichproject from the hollow shaft are shaped as bushings 23 and 24,respectively, of annular cross-section.

In the top and in the bottom of the chest 10, metal strips 25 aremounted, each of which supports a pin 26 and 27, respectively. Thesepins are in alignment with each other and engage the bushings 23 and 24to support rotatably the shaft 20. Owing to its own weight, the lowerend of the bushing 24 rests on a flange 28 carried by pin 27. Betweenthe upper end of the bushing 23 and a corresponding flange 29 of pinthere is an interval which permits to slide the shaft 2 upwards by sucha distance that the bushing is disengaged from the lowerpin 27, which isshorter than the upper pin 26. In order to mount the shaft in its place,its upper bushing 23 is first slid over the longer upper pin 26,whereupon the lower end of the shaft is swung in so as to .bring thelower bushing id into alignment with the lower pin 27, whereupon theshaft 2d is slid downward-s to engage the bushing 24 over pin 27.Removal of the shaft 20 can be effected by displacing it in the oppositeway. To retain the shaft 24} in the position in which it has beenmounted, a pin 3tl'or a cotter pin is removably fitted into a cross-boreof the longerupper supporting pin 26.

The shaft or common locking member 29 carries an arm 31.rigidlyconnected to it and provided with a hole 32 in which a link rod 33 ispivoted. The opposite end ofthis rod 33 engages an arm 34 carried by ahorizontal shaft 35 which is rotatably supported in the chest 1t andcarries a key-receiving member as at the front face of the chest. A key37 can be introduced into member 36 for rotating the shaft 35 wherebythe common locking member 20 is actuated. However, the shaft 35 could beprovided with a handle instead of the key-receiving member 36 at thefront face of the chest 1h.

Preferably, the rotation of the common locking member 20 is limited, bymeans of abutments (not shown) co-operating. with the arm 34- or by anyother known means, to an angle which is equal to one half of the anglebetween two adjacent faces of the shaft 29, that is, to in the presentexample, or to approximately that angle. In one end position of thelocking member 20 its faces are parallel to the walls of the chest 19,as shown in Fig. 4. The face 38 of the locking member which then is atthe rear and extends perpendicularly to thedirection in which thedrawers it are slidable in this case serves as locking surface adaptedto be engaged by the-noses 16 of the locking hooks 14. The commonlocking member 20 is then in its locking position in which it locks thedrawers 11 against being drawn open.

When the drawers 11 are in this closed position, the axis of rotation ofthe locking. member or shaft 26 is in such a position with respect tothe axes of the pins 15 about which the hooks 14 are swingable, and withrespect to the noses 16, that no substantial couple which would tend torotate the said member or shaft 2% out of its locking position can beexerted on that member by means of the locking hooks 14, by. attemptingto draw open the drawers 11. The locking device therefore isself-locking, and it is practically impossible to subject the lock 36 tohigh forces by attempting to draw open one or more of the closed drawers11, therefore, the lock 36 may be'of comparatively light constructionalthough it may serve for looking a large number of drawers.

If by means of the key 37 one rotates the locking member or shaft 20 bysome 45 in the direction of the arrow Q of Fig. 5, into the unlockingposition in .Which it is shown in that figure, the locking surface "3t;assumes an oblique position with respect to the direction in which thedrawers 11 are slidable. The said locking surface 38 thus is lifted offthe co-operating surface 39 of the noses 16, without sliding along thatsurface 39. At the most, the extreme edges of the noses 16 of thelocking hooks 14 remain in contact with the locking surface 38 of member20, as shown in Fig. 5. Therefore, only slight frictional forces betweenthe locking surface 38 and the noses 16 must be overcome when rotatingthe locking member 20 into its unlocking position. During such rotation,one edge 40 at which the locking surface 38 meets an adjacent face ofthe square shaft 20 is displaced laterally towards the locking hooks 14so that the latter are swung out somewhat into an inactive position(Fig. 5). Thereby andowing to the oblique position of the lockingsurface 38, the locking books 14 now are enabled to slide olf from thislocking surface and'from the common locking member 20 as a whole, assoon as one exerts a force on the corresponding drawer 11 in thedirection of drawing it open. The drawers 1. are no longer locked andany of them can be drawn open separately or jointly, and closed again atwill.

Closing of the drawers also is possible when the common locking member20 is in its locking position as shown in Fig. 4. If any drawer not yetclosed is pushed back towards its closed position, the inclined surface19 of its locking hook 14 meets the common locking member 20, wherebythe locking-hook 14 is swung sidewards against the action of its spring18. As soon as the drawer reaches its fully closed position, the nose 16is snapped in behind the locking member 29 by its spring 18, so that thedrawer is automatically locked.

The main advantage of the described locking device consists in that onlycomparatively small forces are required to rotate the common lockingmember 20 from its locking to its unlocking position. This makes itpossible to use one and the same common locking member 20 forco-operating with a very large and hitherto inadmissible number ofdrawers 11 or locking books 14, without impairing the ease with whichthe common locking member can be rotated into its unlocking position.For this reason it is possible with a locking device according to theinvention to lock and unlock up to three hundred or even more drawersfrom one central point. The drawers must not necessarily be arranged oneabove the other but they may also be in a plurality. of vertical rowsarranged side by side, in which case one common locking member 20 willbe provided for the drawers of each vertical row and the several lockingmembers will be connected by suitable linkage or similar means.

Another advantage of the central locking device according to theinvention resides in the fact that the ease with which the commonlocking member 20 can be rotated from its locking position to itsunlocking position is in no way impaired if one simultaneously attemptsto draw open the drawers 11 or if one pushes them rearwardsin thedirection oftheir closing. If the drawers are loaded with heavy objectssuchas tools and if their guiding rails 14 happen to be inclinedforwards or rearwards instead of being horizontal, so that the weight ofthe contents tends to move the drawers into their open or closedposition, the easy operation of the locking device remains unaffected.

A further advantage of the invention is that rotation of the commonlocking member into its unlocking position has no pulling or pushingefiect whatever on the drawers 11, in the direction in which they areslidable. For this reason as well, it is immaterial whether the drawersare empty or heavily loaded.

Further, the described locking device has the advantage that the commonlocking position even if none or only some of the drawers are in theirclosed position. The drawers which have remained open or partly open canbe closed afterwards and then become automatically locked. If some ofthe drawers 11 are nearly but not fully closed when the common lockingmember is rotated into its locking position, the locking surface 38 onrotating in a direction opposed to that of the arrow Q in Fig. 5 engagesthe noses 16 of the locking hooks 14 of 5 the said drawers which arenearly closed and thereby moves these drawers into their fully closedposition.

There is also an advantage of the locking device according to theinvention in the fact that the locking hooks 14 may engage the commonlocking member 20 at any convenient point of its length, so that thedrawers can be arranged at adjustable levelsin the chest 10, or that thenumber of drawers in a given chest 10 can be increased at will withinthe limits imposed by the size of the chest.

Instead of a square shaft as shown a prismatic shaft of othercross-sectional shape could be used as the common locking member.

The locking device according to the invention is suitable for chests ofdrawers, cases, lockers and the like equipped with drawers adapted tocontain tools, documents, index cards, or any other articles.

I claim:

In a chest of drawers having parallel side walls, a plurality of drawerssupported on the side walls and slidable in parallel directions, and topand bottom walls on the top and bottom edges of the side walls, a drawerlocking device comprising a common locking member rotatably supportedbetween said top and bottom walls and rotatable between a locking and anunlocking position about an axis perpendicular to the said paralleldirections in which the drawers are slidable, a pair of fixed alignedpins on said top and bottom walls on which said common locking member isrotatably supported, one of said pins being longer than the other, thesaid common looking member having a pair of aligned end bearings intowhich said pins are respectively engaged, an axial abutment for saidcommon locking member on the shorter one of said pins, and a removablelocating means on the longer one of said pins for axially locating saidcommon locking member against said axial abutment on the shorter pin,said common locking member having a locking surface extending at rightangles to said parallel directions when said common locking member is inits said locking position and obliquely to said parallel directions whensaid member is in its said unlocking position, a plurality of lockinghooks ea h swingably supported on one of said drawers for rotation aboutan axis parallel to the said axis of rotation of the said common lockingmember, each of said hooks having an abutment surface adapted to abutagainst said locking surface of said common looking member when thelatter is in its said locking position, said common locking member beingbetween the abutment surface and the axis of rotation of said hooks,whereby the drawer on which said hook is supported is prevented fromforward motion, means biassing each of said hooks towards said commonlocking member, and each of said hooks being configurated to contactsaid locking surface of the common locking member, when the latter is inits said unlocking position with its locking surface extendingobliquely, whereby forward motion of the drawer on which said hook issupported causes the latter to be swung out by said obliquely extendinglocking surface against the action of the said biassing means so as todisengage said abutment surface of the hook from said locking surface ofthe common locking member.

References Cited in the tile of this patent UNITED STATES PATENTS405,003 lackledge June 11, 1889 1,036,442 Bullock Aug. 20, 19121,462,780 Yanchik July 24, 1923 FOREIGN PATENTS 561,249 Germany Oct. 12,1932

